From 62dab84c81a487d946a5fc37c6df541dd95cca38 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 4 May 2018 14:49:52 -0700 Subject: bpf: btf: Add struct bpf_btf_info During BPF_OBJ_GET_INFO_BY_FD on a btf_fd, the current bpf_attr's info.info is directly filled with the BTF binary data. It is not extensible. In this case, we want to add BTF ID. This patch adds "struct bpf_btf_info" which has the BTF ID as one of its member. The BTF binary data itself is exposed through the "btf" and "btf_size" members. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- kernel/bpf/btf.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) (limited to 'kernel/bpf/btf.c') diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 40950b6bf395..ded10ab47b8a 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -2114,12 +2114,28 @@ int btf_get_info_by_fd(const struct btf *btf, const union bpf_attr *attr, union bpf_attr __user *uattr) { - void __user *udata = u64_to_user_ptr(attr->info.info); - u32 copy_len = min_t(u32, btf->data_size, - attr->info.info_len); + struct bpf_btf_info __user *uinfo; + struct bpf_btf_info info = {}; + u32 info_copy, btf_copy; + void __user *ubtf; + u32 uinfo_len; - if (copy_to_user(udata, btf->data, copy_len) || - put_user(btf->data_size, &uattr->info.info_len)) + uinfo = u64_to_user_ptr(attr->info.info); + uinfo_len = attr->info.info_len; + + info_copy = min_t(u32, uinfo_len, sizeof(info)); + if (copy_from_user(&info, uinfo, info_copy)) + return -EFAULT; + + info.id = btf->id; + ubtf = u64_to_user_ptr(info.btf); + btf_copy = min_t(u32, btf->data_size, info.btf_size); + if (copy_to_user(ubtf, btf->data, btf_copy)) + return -EFAULT; + info.btf_size = btf->data_size; + + if (copy_to_user(uinfo, &info, info_copy) || + put_user(info_copy, &uattr->info.info_len)) return -EFAULT; return 0; -- cgit v1.2.1